Sidney smith



' UNITED STATES SIDNEY SMITH, OF CAMBRIDGE, MASSACHUSETTS.

PATENT GEEICE.

OVEN.

. SPECIFICATION forming part of Letters Patent No. 384,177, dated June5, 1888.

Application filed April 7, 1887. Serial No. 233.991.

.To aZZ whom t may concern:

Be it known that I, SIDNEY SMITH, of Gambridge, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Ovens, of which the following is a specification.

My invention relates to ovens,or stoves provided witliovens, usedchiefly for baking purposes.

My invention has for its object the provision of means whereby an ovenmay be evenly or uniformly heated by the consumption of a minimum amountof fuel, the clogging of the iiues by soot and other products ofcombustion avoided, and other advantages gained, all as hereinafterfully set forth.

Of the drawings accompanying and forming a part of this specification,Figure 1 represents a longitudinal vertical sectional view of a stoveembodying my invention. Fig. 2 represents a transverse section of thesame through the firebox.

Similar letters of reference indicate similar parts in both figures.

a represents the stove-casing; b, the ash-pit; c, the lining of thefire-box; d, the oven; e, an air-tight chamber completely surroundingthe oven, and f f the grate.

Instead of providing the stove with fire-lines around the oven for thepurpose of heating the latter, as is usual in stoves as commonly con`structed, in niy invention the surface of the oven, when the fire andthe products of combustion are usually applied for the transmission ofthe heat to the oven for baking pur-` poses, are enveloped with theair-tight chambere, and the heat of the fire is applied to the outsidesurface of said air-chamber. By heating the air on one or more sides ofthe airtight chamber e the heat will be passed around the entire oven bythe circulation of the air in the said chamber. In the present lexampleI have shown a construction or ar- (No model.)

over stove-ovens as ordinarily constructed is the avoidance of the rearand bottom re-ilues around the oven, which are sure to become filled toa greater or less extent with soot and whatever may be carried into themby the combustion of the fuel, and especially in the case wherebituminous coal and wood and the lighter and non-inflammable fuels areused. It is apparent and well known that said clogging and coating ofthe least accessible fireiiues not only obstructs the draft, butprevents the heat from passing freely to the oven, and also necessitatesgreat care in removing said obstructions, in order to prevent the uttercondemnation of the stove for practical use.

By my invention'only such surface or sur faces as are easy of access aredirectly subjected to the products of combustion, in order to heat theoven, which surfaces, in the present example, as stated, are the fronthand top g, which latter only is liable to become coated with a depositof soot and the like, which matter can be easily removed by taking offthe usual covers, i i, from the top of the stove.

In constructions where the heat is applied to the perpendicular sidesonly of the air-cham` ber e, even this slight inconvenience will beavoided. Y

By my invention the air in the closed airchamber e will be uniformly ornearly uniformly heated throughout, and as a consequence heat the oven duniformly on all sides, preventing the so called burning of the thingbeing baked or roasted on the side next to the re, as is common in ovensas ordinarily constructed. t

j represents a short pipe or tube connecting the interior of the oven dwith an air-space, la, intermediate of the lining of the fire-box andthe adjacent casing of the stove. rlhe lire-box lining is provided witha number of 'holes or perforations, Z, connecting the airspace lc withthe interior of the iirebox, which permits the steam from whatever isbeing baked in the oven to escape into the air-chamber 7c and thenceinto the fire-box or ash-pit below.

In my invention the grate is formed in two parts, one part of which, f,is stationary, and the other part, f', movable on ways m m by a handle,n, or other suitable device. The ob- IOO ject of this double grate is toprovide for the partial or entire closing of the intcrstiees between thegrate-bars for the most economic use of different kinds of fuel. Forinstance, when there is a strong chimney-draft and alarge amount ofhydrogen in the fuel, by nearly or quite closing the openings betweenthe gratebars and admitting air for combustion at or near the top of thefuel, as hereinafter described, greater economy and effectiveness aresecured and a prolonged and steady heat maintained, which steadiness isnecessary for satisfactory Y results. Y i* In making a fire withbituminous coal the most advantageous and economical method is to fillthe fire-box to its proper height with coal and then ignite the coalfirst on top by means of the draft of air for combustion through theperforations Znear the top of the tire'box lining, and through theperforations in the top of the casing o, as hereinafter described, theopenings in the grate being closed by the movement of the grate f to theposition shown in Fig. 2 of the drawings. The grate can be opened, ifdesired, when only the carbon por tion of the fuel remains to be burned.By this a quick fire may be secured, economy in the use of fueleffected, and fuliginous smoke avoided.

The casing o is made removable and is adapted to fit on the flanges ofthe openings at the top of the stove, occupied by the centerpiece andcovers immediately over the fireboX. Said casing has a horizontal top,which is higher than the top of the stove'and is provided with numerousfine perforations. The object of this removable perforated easing abovethe top of the stove is to provide an ample combustion-chamber above thefuel, so that the gases from the coal or wood can be penetrated by theatmospheric air as the latter is drawn down through the saidperforations, thus providing the necessary chemical conditions forperfect combustion-viz., the equivalent of oxygen for. the hydrogen andcarbon and the three perfectly diffused and in contact, atom with atom,and all at a high temperature. v

If desired, the casing ofthe stove surrounding the air-tight chamber eat the points or sides not directly subjected to heat from the lire-boxmay be coated or covered with asbestus or like non-conducting material,and thus confine the heat entirely to said chamber.

I am aware that a perforated pot-hole cover 5 5 has been applied to astove, said cover being of an inverted-V shape and perforated so thatits inclined surfaces will project somewhat above the top of the stovefor the purpose of illuminating the room, as shown in PatentNo. 6o106,688. I am also aware that a horizontal cover which, when in place,is flush with the top of the stove, has been provided with holes toadmit air to the fuel in the fire-box, asV shown in Patent No. 42,968.'My removable easing differs from both of the covers referred to in thatit has imperforate sides supporting a horizontal perforated top, whichis elevated above the top of the stove. The easing therefore addsgreatly to the usual combustionspace above the fuel, besides beingadapted to apport cooking-utensils on its perforated top.

Having thus described my invention, I claiml. A stove havinga lire-box,a space, k, and 7 perforations Z in the liningthereof, an oven, aconfined or dead air chambersurrounding the oven, and a tube or flue, j,extending through one side of said chamber and connecting the upperportion of the oven with the space k, whereby gases, odors, Ste., fromarticles in the oven may escape to the lire-box.

2. In a stove or range, the combination, with the fire-boX, of thebottomless easing o, having ,closed or imperforate sides located abovethe top of the stove and coinciding with an opening therein, andprovided with a horizontal perforated top higher than the top of thestove, the interior of said easing constituting a chamber above the topof the stove communicating with the fire-box and receiving air throughits perforated top to be mingled with the gaseous products of combustionbetween the fire-box and the top of the stove, as set forth.

In testimony whereofI have signed my name A to this speciiicatiomin thepresence of two subscribing witnesses, this 30th day of July, 1886.

SIDNEY SMITH.

Witnesses:

A. D. HARRIsoN, H. BROWN.

